[TowerTalk] Impact of high water table levels on antennas

[Michael Tope]

KS8S/AD8P had a contest station in Deshler, Ohio in the mid 80's (about 
1 hour South of Toledo). With just a ~100' shunt-fed tower they seemed 
to have a stand out signal on 160 meters compared to others in the area 
with similar setups. Dean KS8S mentioned they had a very high water 
table in that area. Also, I remember noticing that there was a region of 
higher than average conductivity on the FCC soil conductivity map in 
that part of Ohio.  Not enough for a firm scientific conclusion, but it 
sure seemed like Dean had some sort of magic dirt under his low-band 
antennas.

73, Mike W4EF.......................

On 11/3/2013 11:42 AM, GARY HUBER wrote:
> Rudy,
>
> I have a similar situation.  My QTH is on a glacial moraine about a 
> tenth of a mile from the crest. There is water bearing clay less than 
> thirty inches down and the soil is the black muck left by the glacial 
> ponding. To top it off, I've mounted my HV-2 w/160m mod and umbrella 
> capacitance hat over two dozen 66 foot radials all over the septic 
> leach field.  A friend who has operated from ZF2 and C6 numerous times 
> says I am very strong using the HV-2 on 40..... I've worked a lot of 
> DX with the HV-2 over the septic field over the past 27 years 
> including ZL9CI, KH1, KH6, etc.
>
> I believe the high water table helps me and will help you.... but the 
> advantage works also for the 4SQ or any antenna. Probably about 3 dB 
> from the Fresnel reflection.
>
>
> -----Original Message----- From: Rudy Bakalov
> Sent: Sunday, November 03, 2013 1:02 PM
> To: towertalk at contesting.com
> Subject: [TowerTalk] Impact of high water table levels on antennas
>
> Ever since I have put up two inv-Vs, one for 80m and one for 160m, 
> with their apexes at roughly 90', I have been puzzled by their 
> exceptional performance. Ditto for my vertical on 40m.  I have done 
> tons of comparisons using skimmer data and my signal seems to be 
> pretty darn close to the big stations I am using as my benchmark. The 
> performance is so good that I have been wondering if I should bother 
> with building 4SQs. I have read tons of books on antennas and the 
> performance of these two antennas simply does not match what the books 
> describe.
>
> I shared my thoughts with a friend of mine (a WRTC2014 participant) 
> and he shared a similar experience with his station. He recently 
> relocated to a new place, about 30 miles from his old place, and his 
> antennas at the new place perform significantly better than the old 
> location. Same antennas, tower, feed line, and FLAT terrain.  His only 
> explanation is that the new place had a very high water table that 
> somehow impacted antenna performance.
>
> This is when I realized that I also have a very high water table. Even 
> in the driest months of summer, the area around my tower is damp and 
> the grass is very green, growing like crazy. This was the obvious 
> common element between his and my situations.
>
> I have not seen anything on high water tables in my antenna books.  
> The soil itself is mostly sandy. The impact I believe I am seeing is 
> mostly on the lower bands, but I am not sure if this is also the case 
> on the upper bands as at 105' my antennas are a bit too high.
>
> Is there any rationale in our thinking? Can high water table explain 
> better than expected performance from low band antennas? If so, what 
> is the theory behind it and how do I take advantage of it? If not, any 
> other suggestions for why the antennas work so well?
>
>
> Rudy N2WQ